org.eclipse.jdt.launching/launching/org/eclipse/jdt/launching/ExecutionArguments.java

package org.eclipse.jdt.launching;

/**********************************************************************
Copyright (c) 2000, 2002 IBM Corp. and others.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Common Public License v0.5
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v05.html

Contributors:
    IBM Corporation - Initial implementation
*********************************************************************/

import java.util.ArrayList;
import java.util.List;

/**
 * The execution arguments for running a Java VM. The execution arguments are
 * separated into two parts: arguments to the VM itself, and arguments to the Java 
 * main program. This class provides convenience methods for parsing a string
 * of arguments into seperate components.
 * <p>
 * Clients may instantiate this class; it is not intended to be subclassed.
 * </p>
 */
public class ExecutionArguments {
	private String fVMArgs;
	private String fProgramArgs;
		
	/**
	 * Creates a new execution arguments object.
	 *
	 * @param vmArgs command line argument string passed to the VM
	 * @param programArgs command line argument string passed to the program
	 */
	public ExecutionArguments(String vmArgs, String programArgs) {
		if (vmArgs == null || programArgs == null)
			throw new IllegalArgumentException();
		fVMArgs= vmArgs;
		fProgramArgs= programArgs;
	}
	
	/**
	 * Returns the VM arguments as one string.
	 *
	 * @return the VM arguments as one string
	 */
	public String getVMArguments() {
		return fVMArgs;
	}
	
	/**
	 * Returns the program arguments as one string.
	 *
	 * @return the program arguments as one string
	 */
	public String getProgramArguments() {
		return fProgramArgs;
	}
	
	/**
	 * Returns the VM arguments as an array of individual arguments.
	 *
	 * @return the VM arguments as an array of individual arguments
	 */
	public String[] getVMArgumentsArray() {
		return parseArguments(fVMArgs);
	}
	
	/**
	 * Returns the program arguments as an array of individual arguments.
	 *
	 * @return the program arguments as an array of individual arguments
	 */
	public String[] getProgramArgumentsArray() {
		return parseArguments(fProgramArgs);
	}	
			
	private static class ArgumentParser {
		private String fArgs;
		private int fIndex= 0;
		private int ch= -1;
		
		public ArgumentParser(String args) {
			fArgs= args;
		}
		
		public String[] parseArguments() {
			List v= new ArrayList();
			
			ch= getNext();
			while (ch > 0) {
				while (Character.isWhitespace((char)ch))
					ch= getNext();	
				
				if (ch == '"') {
					v.add(parseString());
				} else {
					v.add(parseToken());
				}
			}
	
			String[] result= new String[v.size()];
			v.toArray(result);
			return result;
		}
		
		private int getNext() {
			if (fIndex < fArgs.length())
				return fArgs.charAt(fIndex++);
			return -1;
		}
		
		private String parseString() {
			StringBuffer buf= new StringBuffer();
			ch= getNext();
			while (ch > 0 && ch != '"') {
				if (ch == '\\') {
					ch= getNext();
					if (ch != '"') {           // Only escape double quotes
						buf.append('\\'); 
					}
				}
				if (ch > 0) {
					buf.append((char)ch);
					ch= getNext();
				}
			}
	
			ch= getNext();
				
			return buf.toString();
		}
		
		private String parseToken() {
			StringBuffer buf= new StringBuffer();
			
			while (ch > 0 && !Character.isWhitespace((char)ch)) {
				if (ch == '\\') {
					ch= getNext();
					if (ch > 0) {
						if (ch != '"') {        // Only escape double quotes
							buf.append('\\'); 
						}
						buf.append((char)ch);
						ch= getNext();
					} else if (ch == -1) {     // Don't lose a trailing backslash
						buf.append('\\');
					}
				} else if (ch == '"') {
					buf.append(parseString());
				} else {
					buf.append((char)ch);
					ch= getNext();
				}
			}
			return buf.toString();
		}
	}
	
	private static String[] parseArguments(String args) {
		if (args == null)
			return new String[0];
		ArgumentParser parser= new ArgumentParser(args);
		String[] res= parser.parseArguments();
		
		return res;
	}
}